U.S. Pat. No. 6,447,459 (Larom) entitled Device and Method for Measuring Lung Performance, which is incorporated by reference herein in its entirety, allegedly discloses a sophisticated peak flow meter with certain mechanical enhancements that allow for more accurate measurements of certain respiratory functions. The enhancements are allegedly accomplished through novel techniques of dampening oscillations and eliminating the gravitational effects of the flow measurements taken by the device. See Abstract. As a result of the increased sensitivity of the peak flow meter and its respiratory measurement apparatus, more sophisticated and useful statistical measurements, such as one and six second Forced Expiratory Volume measurements (FEV1 and FEV6 respectively) are able to be measured. Further, Larom also allegedly discloses a coupling of the peak flow meter with a microprocessor and a non-volatile electronic memory such that the enhanced respiratory measurements taken by the device are transduced into an electronic format which are then stored in the memory for further transmission by the microprocessor. Larom further discloses a coupling of the microprocessor to any one of a number of warning indicators that may alert the user of a potential problem with the recorded respiratory function, such as the measured respiratory reading being outside a preprogrammed reference range. See Col. 11, I. 66 to Col. 12 I. 16. Such out-of range results may also be disclosed on an electronic display, viewable on the device, coupled to the microprocessor. The display of Larom also displays the enhanced measurements taken by the improved mechanical apparatus, such as FEV1 and FEV6, as well as other measurement calculated by the microprocessor, such a the ratio of FEV1/FEV6. See FIG. 17A and associated description. When coupled to a holding cradle coupled to a computer, Larom also allegedly discloses the transmission of the respiratory data to the computer such that the transmitted date may further be used to creation an electronic diary and/or be transmitted to a physician for interpretation of the measurements. See Col. 2, II. 58-68 and Col. 13, II. 1-19.
U.S. Pat. No. 6,190,326 (McKinnon) entitled Method and Apparatus for Obtaining Patient Respiratory Data, which is incorporated by reference herein in its entirety, allegedly discloses a component system for collecting patient respiratory information including a base unit and a removable mouthpiece. See Abstract. The mouthpiece allegedly includes electronic storage of identification information for a user of the mouthpiece as well as the respiratory measurements taken from the patient during testing. Such measurements may include FEV1 and Peak Expiratory Flow Rate (PEFR). The mouthpiece is coupled to a base unit which, in turn, may be coupled to a data network that transmits respiratory data recorded by the mouthpiece to an attending physician. Electronic display units may be included within the mouthpiece and base unit measurement system for displaying the respiratory data to the patient. Further, intelligent inhalers used for dispensing asthma medication may be coupled to the base unit such that the base unit records the date, time and amount of the medication dispensed by the intelligent inhaler. See Col. 7, II. 35-57. Finally, the base unit is allegedly disclosed to include a patient performance manager in which treatment plans may be programmed by the attending physician either at the office or through the data network. See Col. 5, II. 18-42.
Numerous other enhancements to inhalers or respiratory medication delivery devices are knows, such as those disclosed in U.S. patent application Ser. No. 10/997,278 having common inventorship with the present application, in which the delivery of the medicine is conditioned by the inspiratory flow sensors included on the medicine dispenser.
None of these devices have seen widespread clinical use, however, due to the large volume of raw data they provide. This data overload creates both a treatment dilemma and an associated potential liability for treating physicians. First, physicians do not have the time to review the large volumes of raw date that the all the electronic peak flow meters from all of their patients provide, whether presented as tabular pulmonary data or automatically charted for the ease of physician review. This is particularly true when considering the number of measurements performed per patient during a given monitoring period and the ease with which they may be transmitted over computer networks from home-based pulmonary detection apparatus, even if this only from a significant fraction of the number of asthmatics who by current disease management criteria might benefit from regular use of these devices. Further, health insurers have no current billing paradigm according to which physicians would be paid for their review of this data. This is particularly so in the absence of the following accompanying actions: face-to-face contact with the patient, a full review of the patient's history, an examination of the patient, a formulation of management options, a review of options with the patient or parent, instruction in the details of their implementation, and planning for reasonable ongoing monitoring and follow-up. Second, and more significantly, physicians and their insurers are reluctant to assume the risk of collecting patient data that their attending physicians do not have time to review fearing the liability of potential early warning signs within the unreviewed data, early warning signs that, in the worst case scenario, are indicative of a life threatening status.
Thus the need exists for incorporating certain analytic capacity directly into personal pulmonary function measuring devices, or their immediately accessible and attached equipment, to increase their ability to provide clinically useful information about the stability of and variations in various pulmonary function parameters. This is particularly valuable when the patient's data is monitored, recorded and analyzed regularly, over an extended period of time, i.e. over a monitoring period that would be unobtainable in the presence of a physician and including a significantly greater amount of data than that collected in the physician's office.
As an additional inventive aspect, the need exists for a programmable peak flow meter in which respiratory challenges, such as exposure to a particular asthmatic trigger, may be anticipated and peak flow meter programmed to take readings immediately in response to the trigger. In particular, a meter is needed that prompts for, anticipates and confirms a set of measurements taken without direct oversight by the evaluating physician, including the programming of options and algorithms to cover likely decision points needed by the physician. These would include intelligence within the peak flow meter that 1) prompts the user at appropriate time, such as at programmed intervals following an anticipated challenge, 2) has the ability to identify when users need to use rescue medications, and 3) changes the prompting algorithms to track response to rescue medications if the user indicates that such medications were used.